Model Output Discussion 29th December - Into mid-Winter.

[Ali1977]

Cant post pictures but the GEFS mean at 108 is better than the Op with the cold hanging on way better - could be some epic ENS, and the best set by far this year hopefully.  

[weirpig]

Regarding the snow potential for the next few days   it just shows how hard it is to nail down the specifics   although not HI res  the control brings quite a bit of snow for the majority of England on Fritter friday

[radiohead]

Ridge is pushing a bit further northeastwards on the 06Z GEFS mean than the 0Z. Trends moving in the right direction.

[Panayiotis]

17 minutes ago, winterof79 said:

Could someone please link me to GPs previous post regarding mid Jan "End if world" cold.I have a feeling he nailed a prediction

Thanks in advance

 

Edited January 10, 2017 by Panayiotis

[terrier]

Great output this morning. Gfs comes kicking and screaming towards the euros. But I remain cautious as easterly are a fickle beast to get in the uk. Even seen these go belly up a t72. 

[snowbob]

7 minutes ago, nick sussex said:

I'm really in two minds now about what evolution would get us to the best point. The ECM is far safer, the GFS less but that type of evolution with the shortwave cutting se'wards and ridge building in from the ne generally has the better chance of the high further north. But its just this shortwave business which is driving me a bit nuts!

Perhaps we should have a thread vote? In the interests of model democracy I'll support which solution is the winner and cheer it on!

Nice to have a choice for once nick

gfs or ecm

[Luke Attwood]

59 minutes ago, Ravelin said:

It's positive if you want the GFS to follow the ECM solution, the latter of w

Well the control is way off the mark,with the high collapsing into southern Europe... Mmmm

[bluearmy]

1 minute ago, Luke Attwood said:

Well the control is way off the mark,with the high collapsing into southern Europe... Mmmm

Nah - the control is only ever with looking at when it shows a cold solution !

[Ali1977]

MMMMM, not there yet - by 192 the GFS Op looks like the coldest and best looking set up, hopefully because it's the most powerful model and not because it's incorrect.  I still think more runs are needed until both the ENS are on board - or not.

[Gustywind]

Incredible consistency from ECM, the evolution to a Scandi high pressure looks to be fairly well nailed down now, the only question being does it get far enough north. Not sure it would quite make it on UKMO. 

Love the lows swinging up from the south west on FI 6z, classic Atlantic v Scandi high battleground, which can bring copious falls of snow to central and southern England, especially if the front stalls and doesn't get too far north.

[Seasonality]

Just now, Ali1977 said:

MMMMM, not there yet - by 192 the GFS Op looks like the coldest and best looking set up, hopefully because it's the most powerful model and not because it's incorrect.  I still think more runs are needed until both the ENS are on board - or not.

Most powerful model?

[bradymk]

GEFS still not going for the easterly solution. High further south like the previous GFS runs with the easterly over northern Italy apart from one or two members. Not too much worry though, rather the op showing it, higher res too.

On to the 12z's...

[jvenge]

Just now, Seasonality said:

Most powerful model?

I guess he means the operational being at a higher resolution.

 

[nick sussex]

1 minute ago, snowbob said:

Nice to have a choice for once nick

gfs or ecm

True but we don't want a halfhearted solution, that's the issue I have with the GFS 06hrs run. The shortwave cutting se'wards has to eject cleanly from the energy associated with the elongated PV. You want either full steam ahead with the GFS trend or just the strong vertical as possible ridge with the ECM. At this point I'm minded to back the ECM because its got more margin for error as long as you get the strong ridge to the ne. I maybe over worrying but many of the old timers in here will understand why.

[weirpig]

Just now, Seasonality said:

Most powerful model?

Highest res  compared to its ensembles.

[Ali1977]

3 minutes ago, Seasonality said:

Most powerful model?

Yeah I was wondering that when I wrote it, I believe the Op is more accurate than the ENS therefore more trustworthy - but as a whole package the ENS maybe have a better handle of things.  I'm sure someone can explain better than me.  Anyway, it's still looking good.

 

Highest resolution , thanks that is what I meant...

Edited January 10, 2017 by Ali1977

[Luke Attwood]

6 minutes ago, bluearmy said:

Nah - the control is only ever with looking at when it shows a cold solution !

What do you mean,I was just saying the control is terrible in comparison to the op

[nick sussex]

7 minutes ago, Ali1977 said:

Yeah I was wondering that when I wrote it, I believe the Op is more accurate than the ENS therefore more trustworthy - but as a whole package the ENS maybe have a better handle of thinks.  I'm sure someone can explain better than me.  Anyway, it's still looking good.

 

Highest resolution , thanks that is what I meant...

Easterly evolutions need the higher resolution especially if you're dealing with the GFS shortwave. The fact that so many ECM ensemble members are on board is probably because they're going with the less complex evolution like the op run. You also have to factor in the GEFS bias as they will be more likely to push too much energy over the block.

I should add that if the op drops the easterly then normally its game over even if the ensembles still show a lot of support for it because most of our easterly failures have been in relation to a shortwave tragedy and at closer range the op would handle that better. Anyway lets think positive there is a strong signal for high pressure to the east/ne and our luck is due a change.

Edited January 10, 2017 by nick sussex

[karlos1983]

16 minutes ago, Panayiotis said:

 

I've heard rumblings that teleconnections and LRF tools are a waste of time......

as a southerner I'm liking the signals here, the Scandi heights are edging further north with each run, meaning for once south of the M4 might be the place to be 

nice to see the -10c 2m temp make an appearance on a very nice set of ENS 

Edited January 10, 2017 by karlos1983

[bluearmy]

7 minutes ago, Luke Attwood said:

What do you mean,I was just saying the control is terrible in comparison to the op

sarcasm Luke 

 

[Zakos]

GFS forecast evolution for monday over the last 24 hours.

GFS has been embarrassingly poor in the medium range, how can we trust any output past day 5 when it has made westward corrections every single run for the last 48 hours?

[Weathizard]

The GEFS are slightly worrying, a bit of an uptick from the 0z ensembles despite the much better OP run. Not that I value the ensembles that much in energy splitting situations you need the highest resolution possible, still a slight worry mind you.

 

Lots of them have the high getting squashed into Europe with even the south missing out on the easterly, mind you the GFS has been pretty useless just lately so maybe not having it fully on board is a blessing in disguise

[Cleeve Hill]

On 30/12/2016 at 20:56, Glacier Point said:

Well this is going to be an interesting standoff.

ops jumping around, but we have cmc, gefs and eps means all showing very coherent and cold solutions day 10 onwards, +ve height anomaly centred Iceland, becoming more Greenland over time as the North Pacific ridge retrogressive and pulls the core vortex with it. Cmc until now has been unconvincing on this.

It's worth noting that evolutions to cold patterns have not been straightforward, witness last November. Also problematic is the strong emphasis on the southern arm of the jet and rather diffuse northern arm (as has been the case all winter). Still not totally convinced by the Greenland bit, and would favour Scandinavia as the destination for ridge development. Interesting times, particularly coming against the wQBO / solar backdrop. 

So, 10 days on from 30th December = 9th Jan. and a scandi high favoured. Seems like a great shout GP.

 

[Scandinavian High.]

 Blizzards For southern England south east England white out conditions..

[Nick F]

All this talk of easterlies this morning and it's the 30th anniversary in a few days of the start of the infamous January 1987 beasterly, the Holy Grail of easterlies. The 13th of Jan '87 saw sub -15C T850s spread from the east. Only seems like yesterday I was helping to dig through a snow drift in Kent, aged 11, with my father so we could get our car back home. How time flies!

Anyway, enough reminiscing, looking at the 06z GEFS postage stamps, main concern re: easterly potential is that quite a number of members not really building  the high far enough north and northeast so we don't get a decent a cold easterly flow, with only a few members with a strong and cold easterly flow, but at least the Atlantic looks blocked and will be cold under high pressure inversion. Still chance of cold easterly - despite this IMO.

Edited January 10, 2017 by Nick F